PSB SubSeries 450 Subwoofer Reviewed
Although it’s more of a phobia than a fair judgment, digital signal processing has something of a bad name among audiophiles, but most subwoofer designers will roll their eyes if you proclaim the evils of DSP in their presence. DSP, arguably, has even more benefits for subwoofers than it does for other speakers. Using DSP, a subwoofer designer can deliver products with almost perfectly flat response and can push the driver and amplifier right up to their limits, but not beyond–thus achieving the maximum useful output for a given design. This kind of precision is impractical and sometimes impossible with analog circuitry. It’s why PSB finally bit the bullet and created a digitally tuned subwoofer, the $1,499 SubSeries 450.
The SubSeries 450 packs a 12-inch active driver powered by a 400-watt RMS Class D (digital) amplifier, plus two 10-inch passive radiators. This is something I love to see. Often, designers use a single passive radiator that is the same diameter as the active driver. While this arrangement may look nicer and cost less, it’s a compromise. A passive radiator is there to reinforce bass frequencies below the driver’s resonant frequency. Because the radiator is reproducing lower frequencies, it should have more radiating area than the active driver. Combined, the SubSeries 450’s dual radiators have about 39 percent more radiating area than the single active driver. Using the radiators instead of ports allows the SubSeries 450 to be relatively compact, at 16.25 by 15.75 by 16.5 inches.
The features included on the SubSeries 450 are standard fare: stereo line inputs and outputs, LFE input and output, stereo speaker-level inputs, and knobs for volume, phase, and crossover frequency (50 to 150 Hz). One nice plus here is that the stereo line outputs are high-pass filtered by 12 dB per octave below 80 Hz, which means if you send this signal to your main amplifier, the bass will be filtered out of your main speakers. And that, in turn, means setting your crossover will be easier, and your main speakers will play louder with less distortion. If you’re using a stereo preamp that, like most stereo preamps, lacks a built-in subwoofer crossover, this is a huge advantage.
There’s also a 3.5mm input jack for a 12-volt on/off trigger signal from an AV receiver, preamp, or home automation system, plus a USB jack that’s used to power an optional wireless audio receiver.
As I do with most subs, I placed the SubSeries 450 in my room’s “subwoofer sweet spot,” a position where most subs tend to sound best from my usual listening position. (In my room, that’s just to the left of the right-channel speaker.) I connected the subwoofer to two different systems. The first was a two-channel system using a Classé CP-800 preamp/DAC, a Classé CA-2300 stereo amp and Revel Performa3 F206 speakers, connected using Wireworld Eclipse 7 interconnect and speaker cables. The second was a home theater system using a Sony STR-ZA5000ES AV receiver and NHT Media Series speakers, including two MS Towers, two MS Satellites, and an MS Center. In both the CP-800 preamp and the STR-ZA5000ES receiver, I set the crossover point to 80 Hz.
I have to note that the SubSeries 450 includes no remote control, no special DSP modes for movies or music, and no auto room EQ–which makes its feature package rather Spartan considering the $1,499 price.
I usually start my speaker and subwoofer evaluations with music, but I was more curious about the SubSeries 450’s performance with action movies. Action-movie soundtracks often push compact subwoofers such as this one past their limits. Most of these subs use passive radiators, which don’t produce the chuffing commonly heard with ports but can produce banging and rattling noises that are (in my opinion) often more objectionable than port noise.
So I started by streaming The Finest Hours, a recent movie about Coast Guard sailors rescuing the crew of a stranded oil tanker during a heavy storm. I knew this movie’s soundtrack would include lots of deep-bass energy, so I played the system loud and cranked up the subwoofer level an extra three dB. Despite roughly a third of the movie’s soundtrack being dominated by the crashes of colossal waves, I noticed no distortion from the SubSeries 450 and no signs of distress in the passive radiators. This, I think, shows the benefits of digital signal processing; Paul S. Barton was, apparently, able to wring the maximum possible output from the driver and radiators without ever pushing them beyond their limits, something I have not seen accomplished with analog circuitry.
[iframe src=”https://www.youtube.com/embed/BQmllwTKtqU” width=”560″ height=”315″]
Of course, The Finest Hours is a new movie whose soundtrack I don’t know well. Thus, I knew it was my duty to challenge the SubSeries 450 with material I knew would push its driver and amp to their limits. So I chose the “Face to Face” and “Depth Charged” chapters of the U-571 Blu-ray, which I’ve used to test innumerable products. “NICE!” I wrote when I heard the SubSeries 450 reproduce the sound of the titular submarine’s deck cannon going off. Some subs compress on the sound of the cannon, leaving it sounding more like a “whack” than a boom, but the SubSeries gave the gun the appropriate fullness. It was just as impressive when reproducing the sounds of depth charges a few minutes later. Again, I heard a powerful, tight, precisely controlled boom rather than a whack. I knew that the SubSeries 450, like almost all powered subwoofers, has an internal limiter; however, despite the demands of U-571, I could never hear the limiter kicking in.
[iframe src=”https://www.youtube.com/embed/VMU9Yos0mkk” width=”560″ height=”315″]
I could tell that the SubSeries 450 was a surprisingly good home theater sub, considering its size, but of course I wondered how it would fare with demanding music, which rarely taxes a sub’s power but does reveal its fidelity. “52nd Street” from David Chesky’s CD The Body Acoustic told me. This CD, like most Chesky recordings, features acoustic instruments recorded naturally with little post-processing–in this case, a double bass playing a fast line. Many subs tend to blur the sound of an acoustically recorded double bass into mud because of their inherent resonances, which often make the low notes of a double bass ring longer than they should. With the SubSeries 450, the bottom notes on the double bass sounded perfectly controlled; I could hear the natural resonance of the double bass with no added boom, delay, or lag.
[iframe src=”https://www.youtube.com/embed/kvTgUA3Nfck” width=”560″ height=”315″]
“Dimples” from James Blood Ulmer’s Memphis Blood CD is a different kind of double bass recording. It sounds like the bass player is using a pickup on the bass, either instead of or in addition to a microphone. The pickup enhances the lower notes of the bass, which aren’t strong on their own; the result is a lot more low-frequency power. With some subs, the bass in this case starts to sound like two different instruments: the boomier, more electric-sounding low frequencies with the more acoustic-sounding overtones. With the SubSonic 450, the double bass on “Dimples” sounded completely integrated, again with no added boom, delay, or lag. “This thing really starts and stops fast,” I noted.
Yet another bass style is evident on “Dirty Girl” from Jimmy Vaughn’s Do You Get the Blues. This is straight walking blues, probably recorded on a four-string Fender Precision electric bass. It’s not what we generally think of as a “melodic” bass line, but because it uses mostly chord tones, with relatively large harmonic intervals, the fundamental tones are all over the range between about 40 and 130 Hz. Thus, it covers the second octave of bass and most of the third. Once again, every note sounded super-clean, with no apparent resonance, no limiter jumping in, and no emphasis of any particular notes. It was just a perfect Texas blues groove. (The link here is to a live version, not the studio version I used.)
[iframe src=”https://www.youtube.com/embed/lRnXGNtkFfc” width=”560″ height=”315″]
Click over to Page Two for Measurements, The Downside, Comparison & Competition, and Conclusion…
Here are the measurements for the PSB SubSeries 450 subwoofer. (Click on the chart to view it in a larger window.)
±3.0 dB from 26 to 192 Hz
(1M peak) (2M RMS)
80 Hz 124.9 dB L 115.9 dB L
40-63 Hz avg 121.6 dB 112.6 dB
63 Hz 124.3 dB L 115.3 dB L
50 Hz 121.8 dB L 112.8 dB L
40 Hz 117.4 dB 109.4 dB
20-31.5 Hz avg 108.3 dB 99.3 dB
31.5 Hz 114.1 dB L 105.1 dB L
25 Hz 107.1 dB 98.1 dB
20 Hz 94.1 dB 85.1 dB
16 Hz NA NA
The chart shows the frequency response of the SubSeries 450 with the low-pass filter bypassed (blue trace) and with the internal crossover set to 80 Hz (green trace). It’s easy in this graph to separate the response of the driver (the hump centered at 80 Hz) with the resonance of the passive radiators (the peak at 30 Hz). Below the resonance of the radiators, the response drops quickly–about -36 dB per octave, which suggests there’s a -12dB/octave electronic subsonic filter in place, in addition to the natural -24dB/octave roll off of the radiators. (I confirmed this result with a ground plane measurement, which is probably a little less accurate in this case than the close-miked measurements; it showed a low-frequency extension of 28 Hz.) That sharp roll off explains why the SubSeries 450 has no measurable response at 16 Hz on the CEA-2010 output measurements … AND it also explains why I heard no banging, rattling, or distortion from the radiators even when I pushed the sub beyond its limits. I measured a roughly -16dB/octave low-pass roll off when I engaged the sub’s internal crossover, and the measured -3dB point at the 80-Hz crossover setting was 77 Hz.
Some of the CEA-2010 output numbers are impressive, some not. Considering the SubSeries 450’s size, its result at 63 Hz is very impressive; it delivers +1.5 dB more output here than the much larger and costlier Paradigm Prestige 2000SW. That’s especially great for movie soundtracks because the region around 63 Hz is where you get a lot of the punch in the sound effects used for explosions, car wrecks, and other impacts. And it’s not like PSB just loosened up on the internal limiter to get a good result here because the total harmonic distortion at this frequency was just 9.4 percent. (That may seem like a lot, but subwoofer distortion is nowhere near as audible as, say, amplifier distortion at 1 kHz; anything below 10 percent with a subwoofer is actually pretty clean.)
However, the SubSeries 450’s size, its passive radiators, and its subsonic filtering mean that the output at 20 Hz, while quite good for a sub of its dimensions, is -13.7 dB lower than that of the much larger Prestige 2000SW, and comparably lower at this frequency than what I’ve measured from the big (and in some cases less expensive) subs from specialists such as SVS, Power Sound Audio, and Hsu Research. So basically what you’re getting with the SubSeries 450 in terms of output is something close to world-class in the midbass and about the best you can expect from a small sub in the lower bass.
Here’s how I did the measurements. I measured frequency response using an Audiomatica Clio FW 10 audio analyzer with the MIC-01 measurement microphone. I close-miked the woofer and passive radiators, scaled and summed the results, smoothed the curve to 1/12th octave. I also did a ground plane measurement as a backup. I did CEA-2010A measurements using an Earthworks M30 microphone and M-Audio Mobile Pre USB interface with the CEA-2010 measurement software running on the Wavemetric Igor Pro scientific software package. I took these measurements at two meters peak output. The two sets of measurements I have presented here–CEA-2010A and traditional method–are functionally identical, but the traditional measurement employed by most audio websites and many manufacturers reports results at two-meter RMS equivalent, which is -9 dB lower than CEA-2010A. An L next to the result indicates that the output was dictated by the subwoofer’s internal circuitry (i.e., limiter), and not by exceeding the CEA-2010A distortion thresholds. Averages are calculated in pascals. (See this article for more information about CEA-2010.)
The SubSeries 450 is impressively powerful for its size, but it can’t deliver the ultra-deep, floor-shaking bass that many larger subs can. During the U-571 scenes I played, there’s a part where the submarine passes under a destroyer. The sub’s engine sounds in this scene are extremely low-pitched and tend to make subwoofers distort and/or make their ports chuff or their passive radiators rattle. The SubSeries 450 exhibited no such distress, but neither did it shake the floor. I could hear the vibrations from the sub’s engine, but I couldn’t really feel them.
I suppose some R&B, rock, or hip-hop fans would prefer a sub that sounds a little “looser”–one that has a little more resonance and boom to it. For example, the sound was a little thin when I played “The Immigrant Song” from Led Zeppelin III. The reproduction of the electric bass and kick drum sounded accurate, but it wasn’t as much fun as hearing it through a fatter-sounding sub. However, the SubSeries 450 is obviously intended for those with refined taste in sound, so complaining that it doesn’t sound fat enough is sort of like saying your steak needs ketchup.
[iframe src=”https://www.youtube.com/embed/kEGuHdKn0Lc” width=”560″ height=”315″]
As I noted before, the SubSeries 450 has no fancy features. But for the most part, I don’t consider those necessary. It would be nice to have an auto room-EQ function, but all the subs I’ve tried with good auto room-EQ functions (which include Paradigm’s Perfect Bass Kit, Velodyne’s Digital Drive+, and the system used in the Thiel SmartSub 1.12) cost considerably more than the SubSeries 450. Of course, most receivers and many surround processors have auto room EQ built in, and you can also add a third-party EQ box such as those offered by MiniDSP.
Comparison and Competition
Let’s see, what are your other options for about $1,500? There’s the REL S/2 for $1,549. I haven’t tested it; but, considering its active driver is smaller (10 inches) and it has just one 10-inch passive radiator and a 250-watt amp, it’s hard to imagine the S/2 satisfying serious home theater fans. Of course, RELs are often touted as “musical,” but my educated guess is that whether or not the S/2 sounds more musical than the SubSeries 450 is more a matter of how you set up the sub than the actual sonic character of the sub. It’s important to note that, like the S/2, the SubSeries 450 has speaker-level inputs, although it doesn’t allow you to blend in an LFE signal as the REL subs do.
Similarly, Sumiko has its new S.10 subwoofer; with a 12-inch driver, 12-inch radiator, and 500-watt amp, it seems equipped to challenge the fidelity and power of the SubSeries 450, and it appears to have the same input configuration as the REL S/2. I haven’t tested it, and no price is yet available. Considering the S.9 lists for $999, the S.10 should be somewhere in the SubSeries 450’s price range.
Then, of course, you have products from subwoofer specialists such as SVS, Power Sound Audio, and Hsu Research. One example is the SVS PB12-Plus, a $1,399 ported sub with a 12-inch driver and an 800-watt amp. This sub combines excellent punch and definition with outstanding deep-bass output. It’s hard to fault the PB12-Plus on anything, except that it’s 2.7 times as large as the SubSeries. Or there’s the $1,649 Power Sound Audio S3600i, in most ways the most incredible sub I’ve tested, but it’s even larger than the PB12-Plus, and its black crinkle finish makes it look like a P.A. speaker.
This is not the review I expected to write. Seeing the size and price of the SubSeries 450, I thought I’d be writing a review that said what I usually say about compact and/or audiophile subs–something like, “It blends well with satellite speakers and sounds well-defined, but it doesn’t have the power and kick that home theater fans want.”
The SubSeries 450 is not like that. No, it doesn’t have the awesome ultra-low-frequency power of the big subs from all the subwoofer specialists. But it has enough power to reproduce all but the most extreme low-frequency sound effects in movie soundtracks at high volume with low distortion, and I was unable to find any material capable of pushing the SubSeries 450 past its limits. Plus, it has pitch definition and precision that’s at least the equal of any sub I’ve tried, AND it’s compact and handsome enough to be welcome in most living rooms. None of the hundreds of subwoofers I’ve tested can truly do it all, but the SubSeries 450 comes as close to that description as any I’ve found.
• Check out our Subwoofers category page to read similar reviews.
• PSB C-LCR In-ceiling Speaker Reviewed at HomeTheaterReview.com.
• PSB Debuts SubSeries 450 12-Inch Subwoofer at HomeTheaterReview.com.